Objective To investigate the accuracy of MRI in preoperative grading of astrocytoma (AG) and MRI findings of recurrent patients. Methods 68 patients with AG were selected as the study subjects. Based on the surgical and pathological examination, the accuracy of MRI in diagnosis of preoperative grading of AG was evaluated. The patients were follow up for 1 year after operation. The MRI findings of recurrent patients were analyzed. Results The correct evaluation rate of MRI in tumor grading of AG was 94.1% (64/68) and the accuracy rates in WHO grade I - IV were 86.7% (13/15), 95% (19/20), 96.3% (26/27) and 100.0% (6/6) respectively. After 1 year of follow-up, there were 9 recurrent patients and the recurrence rate was 13.2%. MRI examination showed 13 recurrence foci, 1 homogeneous signal (7.7%) and 12 inhomogeneous (92.3%); There was no enhancement in 0(0.0%), nodular enhancement in 1(7.7%), patchy enhancement in 2 (15.4%), garland-like enhancement in 9 (69.2%) and mass like enhancement in 1 (7.7%). There was 1 case with mild edema around tumor (7.7%), 5 cases with moderate peritumoral edema (38.5%) and 7 cases with severe edema (53.8%). Conclusion MRI examination can play an active role in the preoperative grading and postoperative recurrence evaluation of AG.